The integrated circuit (IC), for broad use recently on a cellular phone or personal digital assistant, is formed with transistors or resistors as many as several hundreds of thousands to several millions on a silicon substrate in a size of nearly a 5-mm square. This plays an important role in device miniaturization and reliability improvement, and device mass production.
In designing an electric circuit for use on an integrated circuit (IC) or the like, it is frequent cases to design an amplifier circuit having a function to amplify a voltage or current of a signal small in amplitude. The amplifier circuit is broadly used because of a circuit requisite for eliminating strain occurrence to stably operate an electric circuit.